balanced power


Hi, could anyone explain to me in short what balanced power means? This is a term that is applied to isolation transformers. I'm using isolation transformers too (I live btw in The Netherlands) but I'm not using ground. Is that what "balanced" means: using a ground? What are the benefits and drawback of balanced power? Thank you in advance.

Chris
dazzdax
In the schemes I've seen at the Equi=tech website I encounter one stable element and that is: ground. So for a proper balanced power a ground is necessary. What to do without a ground? Then balanced power (and common mode rejection) is not possible? I don't understand it completely. It is also confusing when you read that the Wavac isolation transformer (made by Denken Seiki of Japan) doesn't need ground to achieve full "common mode rejection". How could this be possible? Once more: it is confusing!

Chris
Folks - That was really helpful. I've wondered myself what "balanced power" meant. Now I at least have a clue.
Thanks. Chris - good question!
It has everything to do with AC power. The voltage does not matter.

I cannot speak for your country, but in the USA the two poles on the AC electric plug will be either 120V or Zero. Balanced power as I stated before is 60 & 60 180 degrees out of phase; or to put it another way +60 and -60 volts, the difference between the poles is the same 120V which feeds your gear. The noise is canceled out because the 2 poles are exactly 180 degrees out of phase with each other.

So the power in your wall (if it is unbalanced) is 240V and Zero between the 2 poles. Balanced would in essence be +120 and -120 between the 2 poles. Still 240 Volts.

A step-up or step-down balanced devise is just regenerating balanced power at whatever the output voltage is.
I'm sorry guys, despite your clear explanation I still don't understand how the concept of balanced power can be put into practice: is it always necessary to use a step down trannie with dual cores? So for balanced power a neutral conductor is not necessary? I don't understand it. This is apparently to difficult for me. I thought in the US mains voltage is 120V, so what does 240V to do with US mains voltage?
Just noticed you're in Europe. Euro 220V is not balanced and 50Hz. Same principle to transform to 110+/110- (to ground) but I'm not sure what is availble over there. Balanced power does not have a neutral but a ground is still suggested. I also recommend a GFCI but not essential.
Just an FYI... Blue Circle will custom make a balanced Music Ring to step-up or step-down voltages with the required plugs, etc.

I assume others companies will also ??? If you are a PS Audio fan, you could check with Paul McGowan.
Yes, American 240V is balanced.

Some equipment likes balanced power, some indifferent and very few are not compatible. For example, the SFL2 preamp was a completely different animal when fed balanced power, it loved it.

A simple isolation xformer won't do. You need a step-down with dual cores. Also need to derate the output by half. A 240/120 can be wired for balanced output if you put 120V in. I went one step further and used 240V.
is this the same concept used in fully differentially balanced amps and pre amps?
So, if you were able to run 240V equipment in the USA, [changing the outlet receptacle, and running a 240V line to it], would it sound better, since 240V is balanced...isn't it?
In a normal unbalanced power line you have a hot conductor(120V to ground), a neutral conductor(0V to ground) and the ground. This unbalanced configuration permits low level noise contamination to pass through the power line directly to your sensitive audio components.

In balanced power the 120V to ground is converted to two 60V to ground. These 60V signals are 180 degrees out of phase with one another. You still have 120V, 60hz available at the outlet receptacles but the noise has been canceled out by common mode rejection.

I do not know of any drawbacks over unbalanced power. There are many good units out there to choose from.

The above explanation is from the Blue Circle Music Ring Conditioner web page. BC does make international versions in other voltages that incorporate a power bar with the outlets of your choice. For full disclosure, I am affiliated with BC.